Blast-furnace.



No. 697,249. Patented A r. 8, 1902.

e. P.HERR|CK.

BLAST FURNACE.

(Application filed Oct. 1, 1901. (No Model.) 3 Sheets-Sheet I.

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5 i ii ,L "iw n i ii siii \1 Patented Apr. 8, I902.

G. P. HERBIGK.

BLAST FURNACE.

(Application filed Oct. 1, 1901.

3 Sheets-Shem 2.

(No Model.)

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No. 697,249. Patented Apr. 8, I902.

G. HERRICK.

BLAST FURNACE. 7

{Application filed Oct. 1. 1901.1 (No Model.) 3 Sheets-Sheet 3.

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UNTTED STATES GERARD P. HERRICK,

OF NEIV YORK, N. Y.

BLAST-FURNACE.

SPECIFICATION forming part of Letters Patent No.

697,249, dated April 8, 1902.

Application filed October 1,1901. Serial No. 77,243. (No model.)

To coZZ whom it may concern:

Be it known that I, GERARD P. HERRICK, of New York, in the county andState of New York, have invented a new and useful Blast- Furnace, ofwhich the following is a full, clear, and exact description, referencebeing had to the accompanying drawings, forming part of thisspecification, in which- Figure 1 is a horizontal section on the line II of Fig. 2. Fig. 2 is a vertical section on the line II II of Fig. 1.Fig. 3 is a top plan view, partly in section, showing anotherarrangement of the dust-chamber; and Fig. 4 is a vertical section on theline IV IV of Fig. 3. In the operation of blast-furnaces for smeltingore there is a very considerable loss of stock from the furnace, whichis carried olf in the form of flue-dust with the blast-furnace gases.This is especially so in furnaces used for smelting finely-divided ores.Attempts have been made to collect this dust in settling-chambers ofvarious kinds and when a quantity of it has been accumulated to withdrawit from the chamber and discharge it into the furnace either as dust orin the form of briquets; but such devices are unsatisfactory, becausethey are useful only to catch the dust which has already been carriedoif and do not tend to prevent the escape of the dust from the zone offusion.

Referring to the drawings, in which I illustrate my invention in whatIbelieve to be its preferred forms, in Figs. 1 and 2, 2 represents theupper part or throat of a blast-furnace. 3 is a hopper adapted todischarge the stock concentrically within the furnace and provided witha suitable stock-distributer or bell & at the top of the furnace-4'. e.,above the stock-line-which being outwardly directed or inclined servesto distribute the stock from the center outwardly. 5 is a dust-chambersituated above the furnace and preferably concentric therewith, and 6 isa suitablyarched chamber or passage above the hopper and opening ontothe charging-platform 7, so as to give access to the hopper for thecharging apparatus, by which the stock is fed to the furnace. Thedust-chamber 5 communicates downwardly with the throat of the furnacebelow the hopper through openings or passages 8, which are freely andconstantly open for the passage of the gases into the chamber from thefurnace and for the downward discharge of dust from the chamber into thefurnace. 9 9 are bleeder-pipes, and 10 is the bleeder-pipe which leadsto the. downcomer, through which the furnace-gases are conducted for useat the stoves or boilers. ll 11 are suitable explosion-doors. The top ofthe chamber 6 is inclined, so as to cause the discharge of any particlesof dust which may settle thereon, and the chamber itself is supportedsuitably on cross-supports or walls, as shown in the drawings. When thefurnace is in use, the furnace-gases rise through the passages 8 andchamber 5 to the pipe 10. The enlarged size of the chamber 5 decreasesthe velocity of the gas, and thus decreases the force which tends tocarry off the dust particles from the furnace until the force of gravityis equal to orgreater than the force exerted upon the particles by theblast,when the particles or a large portion thereof cease to rise andremain in the chamber. The column of dust which accumulates and is heldin suspension in the chamber 5 acts by gravity and also in the manner ofa mechanical sieve to oppose the escape of dust from the furnace, whilestill allowing the gas to percolate therethrough, for said column isdirectly in the path of the current of gas and is in communication withthe furnace through-the passages 8. The device is therefore self-actingand the dust is in a large measure retained in the furnace, and is thussaved and smelted without the expense of apparatus and labor incurredWhere dust is first collected and then returned. The stock-line is shownin the drawings by dotted lines. The distributor or bell 4: interruptsthe vertical communication between the offtalre or bleeder pipe 10 andthe furnace-stack and deflecting the gases causes them to be more evenlydistributed through the chamber 5. I

In the form of my invention just described the dust-chamber 5 is mainlyabove the hopper. In Figs. 3 and 4 I show a construction in which thechamber is mainly below the hopper and is constituted by verticallyincreasing the normal distance between the stock-line and chargingapparatus and enlarging horizontally the throat of the blastfurnace. 5represents the chamber formed, as just stated, by enlarging the throatof the furnace horizontally and vertically, as above described, but, asin the construction of Figs. 1 and 2, the chamber 5 in Fig. 4 is in freedownward communication with the main stack below the hopper 3 and belowthe charging-platform. From the top of the chamber 5 extend pipes 9 10,and the pipes 10 are connected with the downcomers or olftakepipes whichlead the gases to the point of use. The operation of this form of myinvention is like that above described. The velocity of the gas and sothe force tending to expel the dust are checked in the enlargeddust-chamber 5', and the column of dust therein acts to keep the dust ofthe furnace burden within the zone of fusion, as above explained. I

In both constructions above described the dust-chamber has greatervertical height between the stock-line and the mouth of the offtake-pipethan the ordinary distance between the stock-line and the top of thestack in iron blast-furnaces unprovided heretofore with dust-chambersabove the stock-line, and it is therefore a prolonged chamber, as Wellas being enlarged in cross-section relatively to the furnace-throat, andthe enlargement is transverse to the direction of natural flow of thegases, the purpose being to reduce their velocity. The mouth of theofftake-pipe is situated at such distance from the stock-line that whenthe gases reach the offtake-pipe the force of gravity shall have checkedthe rise of the particles of dust or so much of them as itis desired toretain in the furnace.

The term furnace-throat is used in the description and claims in itsusual significance, meaning that portion of the furnaceshaft at or abovethe stock-line.

The skilled furnace-builder will be enabled from the above descriptionto modify the construction of the apparatus and to apply it in variousforms other than those which I have shown without departure from myinvention, since What I claim is 1. Apparatus for preventing escape ofdust from blast-furnaces, comprising in combination with the furnace andconcentric hopper and an outwardly-directed stock-distributorsituated'at the top of the furnace, a dustchamber situated between thestock-line and the offtake-pipe enlarged transversely to the directionof natural flow of the gases and prolonged upwardly, said dust-chamberopening downwardly and freely into the furnace below the hopper, and anolftake-pipe leading to a place of use and situated at such distancefrom the stock-line that the particles of dust to be retained inthefurnace shall be checked before reaching said oiftake-pipe;substantially as described.

2. Apparatus for preventing escape of dust from blast-furnacescomprising in combination with the furnace and concentric hopper and anoutwardly-directed stock-distributor situated at the top of the furnace,a dustchamber situated between the stock-line and the oEtake-pipe,enlarged transversely to the direction of the natural flow of the gasesand prolonged upwardly,said dust-chamber opening downwardly and freelyinto the furnace below the hopper and forming a passage for the gases atsome part substantially vertical; substantially as described.

3. Apparatus for preventing escape of dust tion that the particles ofdust to be retained in the furnace shall be checked before reaching saidofftake-pipe; substantially as described.

4. Apparatus for preventing escape of dust from blast-furnaces,comprising in combination with the furnace and an outwardly-directedstock-distributer situated at the top of the furnace, a dust-chamberprolonged upwardly above the stock-line enlarged transversely relativelyto the furnace-throat, and opening freely at its base into the furnacebelow the level of the charging-opening, and an oiftake-pipe leading toa place of use from the dust-chamber at such elevation that theparticles of dust to beretained in thefurnace shall be checked beforereaching said ofitakepipe substantially as described.

5. Apparatus for preventing escape of dust from blast-furnaces,comprising in combination with the furnace, a concentric charging deviceand outwardly-directed stock-distributer situated at the top of thefurnace, a dustchamber prolonged upwardly at the top of the furnace andenlarged transversely relatively to the furnace-throat, saiddust-chamber having its blast-inlet solely from the furnace and openingdownwardly and freely into the furnace below the charging-opening, andan offtake-pipe; substantially as described.

6. Apparatus for preventing escape of dust from blast-furnaces,comprising in combination with the furnace, a dust-chamber at the top ofthe furnace, a concentric chargingopening, and a transverse passage 6leading to the charging-opening, said dust-chamber extending above saidpassage; substantially as described.

7. Apparatus for preventing escape of dust from blast-furnaces,comprising in combination with the furnace, a concentric chargingdevice, and an outwardly-directed stock-distributer situated at the topof the furnace, a dust-chamber prolonged upwardly at the top of thefurnace and enlarged transversely relatively to the furnace-throat, saiddust-chamber having its blast-inlet solely from the furnace and openingdownwardly and freely into the furnace through an opening or openingsthrough which the dust enters from and returns to the furnace, and anofftake-pipe leading to a place of use; substantially as described.

8. Apparatus for preventing escape of dust from blast-furnaces,comprising in combination with the furnace and a bell-charging de vicesituated at the top of the furnace, a dustchamber situated at the top ofthe furnace and opening downwardly and freely into the furnace, saidchamber being prolonged vertically and also enlarged horizontallyrelatively to the throat of the furnace, and an oiftake -pipe situatedabove the chargingopening of the furnace and leading to a place of use;substantially as described.

9. In combination with a blast-furnace, a dust-chamber situated abovethe stock-line opening downwardly and freely into the furnace, prolongedupwardly at the top of the furnace-stack and enlarged transversely tothe direction of the natural flow of the gases and relatively to thefurnace-throat, an offtake having its mouth vertically above thedust-chamber and a charging device situated vertically above thefurnace-stack and constructed to deflect the gases outwardly in theircourse to the offtake; substantially as described.

10. Apparatus for preventing escape of dust from blast-furnacescomprising in combination with the furnace, hopper and concentricoutwardly-directed stock-distributer situated at the top of the furnace,and constructed to deflect the gases outwardly, a dust-chamber enlargedtransversely relatively to the furnace-throat, prolonged upwardly at thetop of the furnace and opening freely at its base into the furnace, andan offtake-pipe leading to a place of use from the dust-chamber at suchelevation that the particles of dust to be retained in the furnace shallbe checked before reaching said offtake-pipe; substantially asdescribed.

In testimony whereof I have hereunto set my hand.

GERARD P. HERRICK.

Witnesses:

GEO. B. BLEMING, L. M. REDMAN.

